Titanium.UI.TabGroup style settings ignored on both iOS and Android

I don't know whether I've just missed something in the docs somewhere, but I can't get any Titanium.UI.TabGroup styling to work on either iOS or Android 2.2

I'm using the following code:

var self = Ti.UI.createTabGroup({
        tabHeight: 40,
        activeTabBackgroundColor: '#F47B21',
        tabsBackgroundColor: '#3C0F62'
    });

Neither the height, nor the colours appear in either device. I've also tried applying colours to the Tabs themselves. This too is ignored on both devices.

Have I missed something, or does this stuff just not work?